Control apparatus



April 1951 B. KOONTZ 2,549,209

CONTROL APPARATUS Filed June 26, 1948 2 Sheets-Sheet l Ap 1951 B.KOVONTZ Q 2,549,209

CONTROL APPARATUS Filed June 26, 1948 2 Sheets-Sheet 2 Fig.6.

Imventor Lfi/VO/VT B. IfOONTZ (Ittorneg Patented Apr. 17, 1951 CONTROLAPPARATUS Lamont B. Koontz Minneapolis, Minn assig-nor toMinneapolis-Honeywell Regulator Company, 'Minneapolis, Minn, acorporation of Delaware Application June 26, 1948, Serial No. 35,462

16 Claims. 1

The present invention relates to control devices responsive to aplurality of conditions including thermal radiation. I

Control devices of the heat emissive type and responsive to thermalradiation, air motion and air temperature have generally been confinedto the laboratory, the principal objection to their use. in homes beingthe relatively unattractive appearance of the existing devices and theinability to mount such ,a device on a wall without it being undulyinfluencedby the wall. It is thus an object of this invention to provideanimproved control device responsive to a plurality of conditions suchas thermal radiation, air motion and air temperature.

It is another object to provide a heat emissive control device that isacceptable in appearance and adapted for wall mounting.

It is a further object to provide a control :device responsive to aplurality of conditions including thermal radiation that can be mountedon a wall without being unduly affected thereby and that is capable ofresponding to radiant effects throughout the ,major portion of the room.

It .is an additional object to provide a control device responsive toair temperature, air motion and thermal radiation wherein the portionsof the total response attributable to these different conditions may bevaried.

It .is also an object to provide a heat emitting control device arrangedto deflect convection air currents away from the wall on which thedevice is mounted.

It is another object to provide a heat emitting control device having athermometer so arranged that it will be relatively unaffected by theoperating temperature of said device and will reasonably accuratelyrespond to room air temperature.

These and other objects will become apparent upon a study of thefollowing specification and drawings wherein:

Figure 1 is a front elevation of a preferred .embodiment of the presentdevice.

Figure 2 is a cross-section view taken on the line 22 of Figure 1. v

Figure 3 is a front elevation of a modification of the device shown inFigure l. V

Figure 4 is a cross-sectional view taken on the line 3- of Figure 3. I

Figure .5 is a fragmentary view of the right eleyation of the deviceofFigure 3. 1

Figure 6 is a side elevation of amodification of the present invention.

Figure '7 is a vertical section of the device of Figure 6 taken as shownby the line 1-1 of Figure 8.

Figure 8 is a horizontal section of the device-of Figure 6 taken on theline '8--'8.

Figure 9 is a plan view of a portion of the device of Figure -.6.

Figure -l.0 is a schematic view showing a suggestedmanner of assembly ofthe cylinder of the device of Figures .6 through 9. Figure 11 is asuggested skeleton member for a winding of the device of Figures 1 andv2.

The present control device preferably includes a temperature responsiveelectrical resistor and .is intended to .be substituted for the roomthermostat in control systems comprising an electrical network circuit,such as disclosed in Gille et .al. Patent 2,375,988, issued .May 15,1945, and the eopending application of Wissmiller et al. Serial No.695,014,,filed September 19, 1946, now Patent No.2,524,754,issuedOotober 10, 1950.

Referring to the drawingsdevice ill of Figures 1 and .2 :comprises aconvex heat radiating temperature responsivemember ll said member beingcircular in shape .and constructed of a ma terial having good heatradiating properties and preferably an electrical insulator, such ashard rubber or the like. Member II has two sets of windingsof resistancewire embedded therein, the outer winding .l 2 comprising temperatureresponsive resistance wire of a material such as nickel, the end orconnecting portion l3 of this winding being attached .to a suitableterminal, while the other end or portion 14 of the winding l2 isattaohedto a contact sector l5 of a :rheostat [6. The other winding .I'lembedded in member .I-l comprises resistance wire having a lowtemperature ,coefiicient of resistance, such as Nichrome, and its endsor connecting wires [8 and 1,9 are connected to suitable heaterterminals. Resistor wires l2 and I1 may be embedded or molded in memberII in any suitable fashion or they may be Wound on suitable core memberssuch as 20 in Figure 11 and then assembled and molded as suggestedinFigure 10. The member II is preferably formed with a rearwardlyextending integral hollow mounting stem21l, said mounting stem .be-

,abl-y disposed.

Base member 23 comprises a thin cylindrical wall portion 26 and aconcave bottom or outer portion 21, the portion 21 being arranged'toface outwardly, as shown in Figure 2. Base member 23 is preferably madeof material having low heat capacity and relatively poor thermalconductivity, cellular hard rubber, thin metal, or other suitablematerial being usable for this purpose. To make concave surface 21 mosteffective for reflectin heat, it is covered, or otherwise coated, with ametallic surface such as polished metal foil or leaf of copper, gold, orthe like, these metals being preferable because of their good heatreflecting characteristics and their resistance to tarnishing. Member IIis attached to base means 23 in such a manner that most of the directradiation from member H is either directed outwardly or reflectedoutwardly'from the base portion of the device, said surface 21intercepting direct radiation from member ll toward the relatively nearportions of the Wall to which device H] is attached. Thus, by preventingdirect radiation from member H to the near wall and by providing arelatively long and ineflicient thermal path between member II and thewall, the ability of the wall to absorb heat from the device isminimized.

In addition to stem 2| of device being used for mounting device ll tobase number 23, rheostat I6 is also mounted on this stem by a suitablenut 30, rheostat l6 being adjustable by a knob 3| having a shaft 32extending through the hollow stem 2| and carrying resilient contact armsor wipers 33 and 34, arm 33 moving over contact member and arm 34 Wipingover resistor 35. Rheostat I6 is connected in series with'temperatureresponsive resistance winding U! to thereby vary the resistance ofdevice [0 and thus vary its control point. To carry away the heat thatmay be caused by rheostat [6, as well as to reduce the cross-sectionalarea of wall member 26, slots 36 and 31 are provided, slot 31 beinglocated near the outermost edge of the wall 26 so that induced air flowthrough base 23 will be directed outwardly from the wall.

In operation, this device is connected so that resistance winding 2 andrheostat I6 are connected in series in a network circuit, not shown.Also, heater winding II is connected to a relatively constant source ofcurrent suflicient to cause member II to operate at a temperature ofabout 85 to 95 degrees with a normal ambient room temperature. Then, dueto the elevated temperature of II, the same conditions tending to cool ahuman body in the room by increasing its loss or heat will also tend tocool member Thus, if the air temperature falls, member [i will becooled; likewise, an increase in air movement Will also tend to carryheat away from member H. In addition, member I i will radiate heattoward all cooler objects at a rate dependin upon temperaturedifferences and, because of its convex shape, this radiation will betoward all parts of the room with the exception of the wall portionsrelatively near the device. Thus, anything tending to increase the rateof heat loss from member II will lower its temperature and decrease theresistance of Winding l2.

' Depending upon the relative response to radiation, air motion and airtemperature desired, adjustable insulating member 38 is moved backagainst surface 27 if a relatively large response to air temperature andair motion is desired, whereas, if a relatively larger response toradiation is desired, member 38 is moved forward to abutment with memberII to thereby minimize the eifect of air temperature and motion on theback side of member This adjustment is usu- 4 ally made at the time ofinstallation and need not be changed thereafter.

With member operating at an elevated temperature, it obviously will tendto cause convection currents but because of the concave shape of portion21, these convection currents are deflected outwardly away from the wallto thus minimize smudging of the nearby Wall surface. Also, because ofthe rising air currents passing between members H and 21 tend to inducean air flow through slots 36 and 31, thermometer 40 having its bulb 4|near slot 36 is able to give a reasonably accurate response to room airtemperature.

Device 46, shown in Figures 3, 4 and 5, is generally similar to that ofFigures 1 and 2 and comprises a circular convex heat radiatingtemperature responsive member 41 having windings 48 and 49 correspondingto [2 and I1, respectively. Member 41 has a relatively small diameterstem 50 formed integral therewith and by which 41 is connected to amounting means comprising a shell-like member 5| having a generallycircular wall portion 52 and a concave bottom portion 53, the concaveportion of bottom 53 being arranged to face outwardly and having apolished metallic surface similar to that above described. An adjustableconcave insulating member 55 is movable along stem 50 to a positionwhere it nests against concave portion 53 or it may be moved forward toabut member 41 as shown in Figure 2.

Wires 56 and 51, leading from heater winding 49, are connected tosuitable terminals as is wire 58 of temperature responsive resistancewinding 48, the other end of this temperature responsive resistancewinding being connected to resistor 59 of a rheostat 66. An adjustinglever or arm 6| has attached thereto a flexible wiper 62 which engagesresistor 59 and lever 6| is connected by a wire 63 to a suitableterminal.

Lever 6| extends through a slot '64 in wall 52, with a scale plate '65being formed adjacent slot 64 to indicate the adjustment of 6 I. Slots66 and '61, similar to 36 and 31 of Figure 2, permit air flow throughbase member 5| and an additional baflle plate 68 is arranged between thebulb of thermometer bulb 69 and rheostat to shield the bulb fromradiation from resistor 59. Because of the pinched-in shape of wall 52,a side portion of the wall 52 may be forced outwardly to some extent andslotted, as at 68 in Figure 5, to make the thermometer 69 more readilyreadable.

In operation, this device is the same as that above described with theexception that the control point is varied by adjusting lever 6| insteadof knob 3|. The device shown in Figures 6 through 9 is quite differentin appearance but very similar in function to the devices abovedescribed. This device comprises a cylindrical member Ill attached by apair of supporting arms II to a base member 12, said cylinder member 10being preferably constructed of hard rubber or like material and arm Hand base member 12 being formed of somewhat similar materia1 butpreferably being somewhat cellular in construction to retard heattransmission therethrough. Cylinder member 10 comprises two principalportions, 13 and 14, divided by a plurality of spaced longitudinallyextending grooves 15, the grooves 15'reducing the cross-sectional areaof member 10 between portions 13 and 14 to minimize heat conductivitybetween said portions Front portion 13 has heater wires and temperatureresponsive resistor wires embedded therein, as in the previous example,said heater wires serving to heat the front portion 1'3 and thetemperature responsive resistor wires l responding :to the temperatureof the portion 3.

As an example of how'member 10 may be constructed, Figure 1-0schematically shows cylinder 1 ll built up from a relatively thin wallcylindrical member Illa, to which is joined and suitably molded asemicylindrical portion 10b, portion 10b being of suflicient thicknessso that it and 10a equal the full thickness of'member 10. However, forthe front portion of cylinder 10, aflrst relatively thin semicylindricalmember 100 has the heater wires 16 wound thereon. Another similar memberwithout wires, 10d is then arranged over 100. Another sem'icylindricalmember l-llc has temperature responsive resistance wire 11 woundthereon, and the outer layer of this composite construction is formed bya relatively thin semicylindrical member '10 Upon assembling cylinder10, as schematically suggestedin Figure 10, the composite cylinder isthen subjected to heat and pressure for vulcanizing or molding the partsinto a single homogeneous cylinder, by methods known in the art. At thetime of this molding, or afterwards, grooves li'm a-y'be formed in thesaid cylinder. 7

The connecting wires for element 16 and '11 may be led into base member12 through supporting arm-s H in any suitable fashion and the heaterwires connected to terminals, as before. Also, one of the temperatureresponsive resistor connection wires may be connected to a terminal andthe other connected to a rheostat T8 in the same manner previouslydescribed. A pair of relatively thin and polished metal plates 19 and 80are disposed in spaced relationship in grooves and have their upper endsbent outwardl as shown in Figure '7. These members 19' and 80 operate toprevent direct radiation of heat from portion 13 to portion 14 of thepresent device, and rising air currents through cylinder 10 aredeflected outwardly by the outwardly bent ends of plates 79 and 80.

If desired, a cap structure 8| may be provided for cylinder Ill, saidcap structure having a pair of openings 82 and :83, opening '83 being onthe I back side of plate 8.0 and opening 82 being forward of plates '19and 80, In addition a pair of pivotally mounted closure members 84 and85 may be mounted on a stem 86 of cap portion 8'! to permit anadjustment of the size of opening 82 to thereby vary the proportionateresponse of the present device to radiation and to air temperature. Whenmembers 84 and 85are arranged to close opening 82, then air movement ispermitted only over the outer surfaces of portion 13 whereas, whenopening 82 is opened, air motion is permitted on both sides of portion13 thereby increasing the response of this device to changes in airtemperature and air motion.

In operation, the device of Figures 6 through 9 is similar to that ofFigures lthrough 5 and may be used in a condition controlling networkcircuit instead of the more conventional resistance thervmostat.

In addition to the modifications shown above, many other substitutionsand equivalents will occur to one skilled in the art, hence the scope ofthe present invention is to be determined only by the appended claims.

I claim:

1. In a condition responsive control device, a base member adapted to beattached to a wall and having a circular wall :and an outwardly facingconcave portion, a circular convex member having a rearwardly extendingstem member.for attaching said convex member in spaced relation to saidconcave portion, heater means for said convex member, temperatureresponsive means in heat exchange relationwith said .convex member, saidconcave member being of greater diameter than said convex member andarranged to intercept at least a major portion of direct radiation fromsaid convex member to ward a wall on which said device may be located, aheat refiectivesurface on the outer faceof .said concave portion, and aconcave member arranged to be moved along said stem from a positionadjacent said concave portion to a position engaging the back side ofsaid convex mem ber to thereby variably insulate the back side of saidconvex member from the surrounding air.

2. In a condition responsive device, a base member having a circularwall and an outwardly facing concave portion, a heat reflective surfaceon said concave portion, a circular convex member of less diameter thansaid base member and having a stem for attaching the same in spacedrelation to said concave portion, heater means for said convex member,temperature responsive means in heat exchange relation with said convexmember, said stem having only sunicient cross-sectional area to providethe necessary mechanical strength for said device to thereby minimizeconductive heat flow from said convex member to said base member, andslots in said base member to permit air circulation through said basemember and to minimize heat transfer from said convex member to a wallon which said device may be be mounted.

3. In a condition responsive control device of the heat emitting type, amember for radiating heat, a heater for said member, means responsive tothe temperature of said member, heat reflective means arranged toreflect heat from said member outwardly, and heat insulating meansadjustably arranged between the first named heat reflective means andsaid heat radiating member.

4. In a condition responsive control device of the heat emitting type,means for mounting said device on a wall of a room, a member forradiatingheat, a heater for said member, means responsive to thetemperature of said member, a reflector member for reflecting heatradiated by said member away from said wall, and means 'for variablyinsulating a portion of said member from the surrounding air.

5. In a condition responsive control device of the heat emitting typeadapted to be mounted on a wall, a radiating member, a heater for saidmember, means responsive to the temperature of said member, a concavereflector member arranged in spaced relation to said radiating memberfor minimizing the direct radiation of heat from said radiating memberto said wall, and manually operable means for adjustably insulating aportion of said radiating member from the surrounding air.

6. In a control device responsive to a plurality of conditions affectinghuman comfort, a convex member, means for heating said member,temperature responsive resistance means in heat exchange relation withsaid member, mounting means for securing said member in spaced relationto a wall of a room, said mounting means being constructed and arrangedto provide a conductive heat flow path of small cross-sectional area,heat reflective means for reducing heat transfer from said member towardsaid mounting means.

7. In a control device responsive to a plurality of conditions affectinghuman comfort and adapted to be mounted on a side wall of a room, aconvex member, mounting means for said member including a base spacedfrom said member, an electric resistance heater having a low temperaturecoefficient of resistance for heating said member, a resistancetemperature responsive means having a relatively high temperaturecoeflicient of resistance in heat exchange relation with said member,and concave heat reflective means arranged between said member and saidbase and in spaced relation to said member for reflecting heat anddeflecting air currents away from said wall.

8. In a condition responsive device of the heat emissive type, a convexmember having a hollow attaching stem and having a temperatureresponsive resistor embedded therein, a mounting means for said memberhaving a generally circular wall portion and a concave reflectorportion, said reflector portion having a metallic heat reflectivesurface, slots in said wall portion, said hollow stem and said mountingmeans providing a relatively long and restricted path for heat flow, arheostat behind said concave portion, a manual adjusting knob having ashaft extending through said hollow stem for adjusting said rheostat,and a baffle plate arranged between said convex member and said mountingmeans and movable along said hollow stem.

9. A condition responsive control device for mounting on a wall of aroom comprising a base member, a convex radiating member arranged inspaced relation to said base member, said convex member includingtemperature responsive means, means for adding heat to said member, areduced section connecting means between said convex member and saidbase member, said connecting means comprising a relatively poor path forheat flow between said convex member and said wall to which said deviceis adapted to be attached, said base member being shaped and arranged toprevent direct radiation from said convex member to such a wall in theimmediate vicinity of said device.

10. In a heat emitting control device, a mounting plate, a hollow basemember attached thereto, said base member having an annular wall portionand an outer concave portion, said base member being arranged over themounting plate with said concave portion facing outwardly, a heatreflective coating on said concave portion, a convex radiating memberhaving a hollow stem attached to said concave portion to hold saidconvex member in spaced relation to said concave portion, heater wireembedded in said convex member, temperature responsive resistance meansembedded in said convex member, a rheostat arranged between said basemember and said mounting plate, and manual adjusting means including ashaft extending through said hollow stem for adjusting said rheostat.

11. In a condition responsive control device of the heat emissive type,a convex member, heater means for said member, means responsive to thetemperature of said member, said member having a hollow attaching stem,a mounting means for said member including a concave heat reflectingoutwardly extending portion to which said hollow stem is attached, amanually adjustable means for said temperature responsive meansincluding a knob arranged in the outer face of said convex member andhaving an operating shaft extending through said hollow stem, and amovable concave member which may be adjusted to nest with said concaveportion or to abut with said convex member. 12. In a conditionresponsive control device, a cylindrical member, a mounting base forattaching said member to a wall, strut-like means for connecting saidmember in spaced relation to said base, a plurality of spaced sectionreducing longitudinally extending grooves in said member arranged toform heat flow restrictions between the front and rear portions of saidmember, means for heating the front portion of said member, heatreflective means arranged to cooperate with said grooves for thermallyisolating the front portion of said member from the rear portion of thesame, said reflective means being constructed and arranged to deflectupwardly moving convection air currents outwardly from said device, andtemperature responsive means in heat exchange relation with the frontportion of said device.

13. In a condition responsive control device, a cylindrical member, amounting base for attaching said member to a wall, structural means ofrelatively small cross-sectional area connecting said base in spacedrelation to said member, a plurality of section reducing spacedlongitudinally extending grooves in said member arranged to form heatbarriers between the outer portion and the rear portion of said member,heat reflector means arranged to cooperate with said grooves inthermally isolating the outer portion of said member from its rearportion, temperature responsive means in heat exchange relation with theouter portion of said member, means for heating said outer portion, andmeans for restricting convection air currents through the space betweensaid reflective means and said outer portion.

14. In a control device responsive to a plurality of conditionsaffecting human comfort, a convex member, means for heating said member,temperature responsive resistance means in heat exchange relation withsaid member, mounting means for attaching said member in spaced relationto a wall, said mounting means being constructed and arranged to providea relatively poor thermal path from said member to said wall, heatreflective means for minimizing thermal radiation from said convexmember in the direction of said mounting means, a rheostat connected incontrolling relation to said resistance means, a manually operable meansextending through said convex member for adjusting said rheostat, andadjustable bafiie means located between said convex member and saidreflective means to control air flow over said convex member.

15. In a control device responsive to radiant heat, a mounting base forsaid device for securing it to a side wall of a room, an exposed heatradiating element spaced from said base, means for heating said element,means responsive to the temperature of said element, connecting means ofrestricted cross section between said element and said base, and heatreflective means between said element and said base, said heatreflective means being shaped and arranged to deflect convection aircurrents away from said base.

16. In a control device responsive to a plurality of conditionsaffecting comfort, an exposed heat radiating element, means for heatingsaid element, means responsive to the temperature of said element, awall mounting base for said element, connecting means for spacing saidelement from said base, and heat reflective means between said elementand said base, said heat reflective means being proportioned andarranged to shield only a relatively restricted area in the plane of thebase from direct radiation from said element and for deflectingconvection air currents away from the plane of said base.

LAMONT B. KOONTZ.

REFERENCES CITED The following references are of record in the file ofthis patent:

Number Number 10 UNITED STATES PATENTS Name Date Hornung July 25, 1933McCabe June 13, 1939 Lauck Apr. 1, 1941 Haines Nov. 4, 1.941 Rylsk Feb.17, 1942 Koontz July 8, 1947 Curry Dec. 21, 1948 FOREIGN PATENTS CountryDate Germany 'Aug. 30, 1927'

